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Biomedical subjects

H Tsuru

Publications and source records attributed to H Tsuru.

At least 109 records · Page 6Linked to original sources
PubMed1986

Initial bone-implant interfaces of submergible and supramergible endosseous single-crystal sapphire implants.

Three types of bone-single-crystal sapphire implant interfaces were histologically determined in submergible and supramergible implant: direct bone apposition (type I), thin connective tissue with poor collagen fibers (type II), and dense fibrous connective tissue (type III). Type I interface was predominant and type III interface was sparsely seen in submergible implants. In contrast to these findings, type III interfaces frequently appeared in supramergible implants, primarily at the apical region. These differences were considered to occur by the biomechanical variable of postoperative healing.

Aluminum↗
PubMed1986

Cell-surface hydrophobicity of Candida species as determined by the contact-angle and hydrocarbon-adherence methods.

Cell-surface hydrophobicities of six Candida species were studied by two methods: measurement of the contact angle, and partitioning with aqueous-hydrocarbon (n-octane, n-hexadecane and p-xylene) mixtures. C. tropicalis, C. glabrata and C. krusei adhered better to the hydrocarbons than did C. albicans, C. stellatoidea and C. parapsilosis. Contact angles for the less adherent species were smaller than those for the more adherent species. Thus the two methods gave results that were similar overall and indicated that C. tropicalis, C. glabrata and C. krusei have greater cell-surface hydrophobicities than C. albicans, C. stellatoidea and C. parapsilosis.

Adhesiveness↗
PubMed1986

Time course of the development of pre- and postjunctional supersensitivity in the rabbit ear artery after decentralization.

Changes in the sensitivity of the rabbit ear artery to exogenous norepinephrine and potassium and to sympathetic nerve electrical stimulation were examined in vitro following decentralization which was performed by removing the unilateral preganglionic nerve proximal to the superior cervical ganglion. The contralateral side was left intact as a control. The postjunctional supersensitivity to exogenous norepinephrine and potassium had fully developed one week after the decentralization and was sustained for at least 8 weeks; the arteries decentralized for 1-8 weeks were about 2.1- and 1.3-fold supersensitive to norepinephrine and potassium, respectively, as compared with the contralateral control arteries. The frequency-response curve of the electrically stimulated decentralized artery shifted gradually to the left of the control within weeks after decentralization. Since the response to electrical stimulation was attributed to endogenous norepinephrine released from the sympathetic nerve terminals within the adventitial-medial junction, the leftward shift of the frequency-response curve in the decentralized artery probably reflects a gradual increase in the released norepinephrine per pulse by electrical stimulation, i.e., the prejunctional supersensitivity to electrical stimulation. It is concluded that the prejunctional sympathetic supersensitivity to electrical stimulation develops slower than the postjunctional nonspecific supersensitivity in the rabbit ear artery. The change in the sensitivity of the denervated postganglionic neuron, including the superior cervical ganglion is also discussed with regard to the "law of denervation supersensitivity".

Animals↗
PubMed1985

Tissue reaction to implanted biomaterials.

Tissue reactions to the single-crystal sapphire, titanium, Co-Cr-Mo alloy, and PMMA were histologically evaluated after implantation into the subcutaneous tissue and tibia of rats. In subcutaneous tissue the reaction from early necrotic change and acute inflammation to final encapsulation by fibrous connective tissue was least pronounced around single-crystal sapphire implants. Tissue reactions of a slightly greater degree were found around titanium and Co-Cr-Mo alloy implants. The most prominent tissue reaction was observed around PMMA implants. In the tibia, single-crystal sapphire, titanium, and Co-Cr-Mo alloy implants were encapsulated by newly formed compact bone, but bone was not so evident around PMMA implants. These findings suggest that single-crystal sapphire implants have more favorable tissue compatibility than those of titanium, Co-Cr-Mo alloy, and PMMA.

Aluminum Oxide↗
PubMed1985

Hydrophobic interaction in Candida albicans and Candida tropicalis adherence to various denture base resin materials.

The effects of hydrophobicities of substrate surfaces on microbial adherence were examined by using Candida albicans and Candida tropicalis and 21 denture base resin materials. With increasing surface free energy of resin plates, increasing adherence of C. albicans and decreasing adherence of C. tropicalis were observed. The surface free energy of C. albicans is higher than that of all resin material surfaces, and C. tropicalis has surface free energy lower than that of all materials used. In calculation of the changes of free energy accompanying the adherence, the higher adherence tendency was accompanied by a lower value for the free energy change in both species. From a different standpoint, the closer the surface free energy of the substrate surface and the microorganism, the higher was the probability of adherence.

Candida↗